1. Field of the Invention
The present invention relates to unified voice messaging systems enabling voice, fax, and e-mail messages to be retrieved via a telephone.
2. Description of the Related Art
The evolution of the public switched telephone network has resulted in a variety of voice applications services that can be provided to individual subscribers and business subscribers. Such services include voice messaging systems that enable landline or wireless subscribers to record, playback, and forward voice mail messages. However, the ability to provide enhanced services to subscribers of the public switched telephone network is directly affected by the limitations of the public switched telephone network. In particular, the public switched telephone network operates according to a protocol that is specifically designed for the transport of voice signals; hence any modifications necessary to provide enhanced services can only be done by switch vendors that have sufficient know-how of the existing public switched telephone network infrastructure.
A particular concern involves existing voice messaging systems, where voice mail storage is highly restricted in both function and capacity due to limited voice mail system features implemented by switch vendors. In particular, all voice and fax messages are typically held in a single inbox, and are categorized based on whether the user has listened to the messages; hence, voice mail users are forced to keep their messages in a single inbox. In contrast, existing e-mail clients executed by computers enable users to store and manage e-mail messages in multiple folders that are customized by the users. Hence, existing voice mail messaging systems designed and implemented according to the conventional public switched telephone network paradigm are highly restricted in the availability of advanced voice mail system features.
An open standards-based Internet protocol (IP) network, such as the World Wide Web, the Internet, or a corporate intranet, has provided dramatically-improved client-server type application services for clients by enabling the clients to request application services from remote servers using standardized protocols, for example hypertext transport protocol (HTTP). The web server application environment can include web server software, such as Apache, implemented on a computer system attached to the IP network. Web-based applications are composed of HTML pages, logic, and database functions. In addition, the web server may provide logging and monitoring capabilities. In the case of services such as electronic mail, the Internet Message Access Protocol (IMAP) enables clients to access electronic mail or bulletin board messages that are kept on a mail server, such as a shared server. Hence, a client e-mail program can access and manage e-mail messages stored on a remote IMAP server from a desktop computer at home, a workstation at the office, or a notebook computer while traveling, without the need to transfer messages or files back and forth between these computers.
Commonly-assigned, copending application Ser. No. 09/480,485, filed Jan. 11, 2000, entitled Application Server Configured for Dynamically Generating Web Pages for Voice Enabled Web Applications, the disclosure of which is incorporated in its entirely herein by reference, discloses an application server that executes a voice-enabled web application by runtime execution of extensible markup language (XML) documents that define the voice-enabled web application to be executed. The application server includes a runtime environment that establishes an efficient, high-speed connection to a web server. The application server, in response to receiving a user request from a user, accesses a selected XML page that defines at least a part of the voice application to be executed for the user. The XML page may describe any one of a user interface such as dynamic generation of a menu of options or a prompt for a password, an application logic operation, or a function capability such as generating a function call to an external resource, such as an IMAP message store. The application server then parses the XML page, and executes the operation described by the XML page, for example dynamically generating an HTML page having voice application control content, or fetching another XML page to continue application processing. In addition, the application server may access an XML page that stores application state information, enabling the application server to be state-aware relative to the user interaction. Hence, the XML page, which can be written using a conventional editor or word processor, defines the application to be executed by the application server within the runtime environment, enabling voice enabled web applications to be generated and executed without the necessity of programming language environments.